Optimizing the use of the ladybird Chilocorus nigritus (F.) as a biocontrol agent
Submitting InstitutionCanterbury Christ Church University
Unit of AssessmentAgriculture, Veterinary and Food Science
Summary Impact TypeEnvironmental
Research Subject Area(s)
Environmental Sciences: Environmental Science and Management
Biological Sciences: Ecology, Zoology
Summary of the impact
Research carried out at Canterbury Christ Church University (CCCU) since
1998 has led to the establishment of the ladybird, Chilocorus nigritus,
as a viable biocontrol agent (BCA) in UK glasshouses. However, integrated
pest management (IPM) programmes involving C. nigritus sometimes
inexplicably fail. The specific impact claimed here relates to research at
CCCU, in collaboration with the Royal Botanic Gardens Kew and the Natural
History Museum, which has improved the efficacy of utilising C.
nigritus for biocontrol.
Specifically, this research has:
1) optimised protocols for growth and use of C. nigritus,
2) resulted in changes in practice at the Royal Botanic Gardens Kew, and
3) changed the advice given by the companies selling C. nigritus
as a biocontrol agent.
Please note that numbered citations refer to outputs in section 3.
The ladybird, C. nigritus was introduced into the UK at the Wye
campus of Imperial College London in 1992 and in 1993 a general release
licence was obtained under the Wildlife and Countryside Act (1981). Since
then, it has been reared and sold in the UK as a biological control agent
(BCA) for armoured scale insects. These scale insects are serious pests of
temperate and tropical crops, both in glasshouses and in temperate and
tropical regions. Chilocorus nigritus therefore forms an important
part of the increasing armoury of BCAs available to organic growers and
those practising IPM.
All research was undertaken at CCCU by Dr Ponsonby (employed CCCU
1995 to present), who coordinated collaborations, authored papers and
supervised PhD students working on the project. Underpinning research was
published between 1998 and 2007 [1-6]. The impact claimed here relates to
the changes in protocols, practice and advice that principally derive from
the work published in 2007, and the subsequent interpretation and
application of that work (see ).
The key findings of the underpinning research can be summarised as
1) Climatic conditions: In collaboration with Imperial College
London and Wyebugs (a company providing insect diagnostic and support
services and the major UK supplier of C. nigritus), Dr Ponsonby
and colleagues established the climatic conditions required for the mass
rearing of C. nigritus and its main prey, Abgrallaspis
cyanophylli, and the conditions required for efficacious deployment
in glasshouses and field situations [1,2].
2) Prey-Relations and deployment: Introductions of C. nigritus
sometimes fail to establish, even when conditions are apparently
favourable. Work undertaken at CCCU from 1998 addressed the complexities
of the prey relations of C. nigritus in the context of glasshouse
use [3-6]. This research determined the prey densities necessary for
successful establishment of C. nigritus, identified the preferred
prey species/combinations and documented indicators of plant/prey
interactions that may affect the efficacy of C. nigritus as a BCA
In combination, this research led to clearly defined work practises and
the publication of definitive introduction rates for C. nigritus
References to the research
1) Ponsonby, D.J. and Copland, M.J.W. (1998) Environmental
influences on fecundity, egg viability and egg cannibalism in the Scale
Insect Predator, Chilocorus nigritus (F.) (Coleoptera:
Coccinellidae). BioControl 43, 39-52.
2) Ponsonby, D.J. and Copland, M.J.W. (2000) Environmental
effects on the development and survival of the scale insect Abgrallaspis
cyanophylli (signoret) (Homoptera: Diaspididae) in relation to its
use as a host for rearing biological control agents. Biocontrol
Science and Technology 10, 583-594.
3) Ponsonby, D.J. and Copland, M.J.W. (2000) Maximum feeding
potential of larvae and adults of the scale insect predator, Chilocorus
nigritus (F). with a new method of estimating food intake. BioControl
4) Boothe, R.A. and Ponsonby, D.J. (2006) Searching behaviour in
Chilocorus nigritus (F.) (Coleoptera: Coccinellidae). Communications
in Agricultural and Applied Biological Sciences 71: 253-261.
5) Ponsonby, D.J. and Copland, M.J.W. (2007a) Aspects of prey
relations in the coccidophagous ladybird Chilocorus nigritus
relevant to its use as a biological control agent of scale insects in
temperate glasshouses. BioControl 52: 629-640.
6) Ponsonby, D. J. and Copland, M. J. W. (2007b) Influence of
host density and population structure on egg production in the
coccidophagous ladybird, Chilocorus nigritus F. (Coleoptera:
Coccinellidae). Agricultural and Forest Entomology 9, 287-298.
7) Ponsonby, D.J. (2009) Factors affecting utility of Chilocorus
nigritus (F.) (Coleoptera: Coccinellidae) as a biocontrol agent. CAB
Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and
Natural Resources 4, No. 046, 20 pp. doi: 10.1079/PAVSNNR20094046.
All work has been published in peer-reviewed journals and this remains
the only peer-reviewed literature available on climatic conditions
required for the growth and rearing of C. nigritus. Peer-reviewed
papers have been cited within the academic (peer-reviewed) and
non-academic literature and were extensively cited in a major recent
international text book on Coccinellid (ladybird) ecology.
Details of the impact
Please note that lettered citations refer to evidence sources in section
5 and that numbered citations refer to outputs in section 3.
The ladybird, C. nigritus is economically important as a BCA in
many parts of the World. It has few natural enemies, reproduces rapidly in
response to pest numbers and has an excellent capacity to coexist in
stable relationships with other natural enemies of pests. Work at CCCU has
allowed the provision of a suitable, sustainable control of armoured scale
insects in UK glasshouses where previously none existed [A] and has
informed the use of the species internationally [B,C].
Within the UK, C. nigritus is particularly important in
situations where pesticide use is problematic (e.g. in butterfly houses,
or in botanical collections open to the public). As these are also the
situations where the unsightly damage caused by scale insects is often of
most concern, effective and safe control of the pest is a priority.
Beneficiaries therefore include both biocontrol companies selling this
species and users of this BCA.
As a direct consequence of this work, C. nigritus now occupies a
small, but extremely important, sector of the BCA market, with sales by
WyeBugs, and through them by BCP ltd (Certis Europe), steadily increasing
as protocols for efficacious use have improved [A]. At present C.
nigritus is the only commercially available BCA for armoured scale
insect control in the UK. Worldwide, this BCA also continues to gather
economic importance in both tropical and subtropical regions, and it now
forms an important part of the natural enemy complex of IPM programmes
globally (e.g. [B,C]).
Research findings on prey relations and population monitoring pest
management have modified and informed the advice given by biocontrol
companies to glasshouse managers in the UK, Europe and around the world.
Such advice includes the climatic conditions required for successful
establishment in glasshouses, suitable times of the year for
introductions, information on the type of prey (pest) present and the
likely effect of the introduction on pest populations, modification of
cultural practices (e.g. cease hosing down during introductions) and
advice on deployment of the beetle in IPM systems.
Interaction with beneficiaries include the following examples.
1) Biocontrol trials at the Royal Botanic Gardens Kew (2009-2010) which
directly resulted in changes to how Kew handles release of the BCA [D].
2) Advisory meetings with pest control staff at the Eden Project (2008)
which informed them of the conditions needed for the BCA to be effective
and indicated the specific pest combinations most likely to result in
successful deployment of the beetle [E].
Impact has therefore specifically occurred where C. nigritus has
been released as a BCA and specific beneficiaries therefore include the
Royal Botanic Gardens Kew (2009 and 2010) [D] and the Eden Project (2009)
[E]. For these beneficiaries, the availability of effective BCAs is
particularly important given the reputational value they place on not
using pesticides. Numerous butterfly farms and indoor landscapes have also
benefited from this work [A] and there is strong evidence on product
websites and from verbal communication that the research has been used by
biocontrol companies and growers worldwide to modify production processes
and pest management practice (e.g. [B,C]).
Sources to corroborate the impact
List of independent corroborators for whom the research has had
A) Wyebugs Ltd. (Contact ID.1)
B) Bugs for Bugs, Australia. (Contact ID.2)
C) Citrus Research International, South Africa. (Contact ID.3)
D) Royal Botanic Gardens, Kew. (Contact ID.4)
E) Eden Project. (Contact ID.5)